GNU Affero General Public License v3.0
Like GPL, but the copyleft extends to network use. If you run it as a service, you must share your source.
Commercial use
✓ Yes
Modify
✓ Yes
Distribute
✓ Yes
Must open source changes
✓ Yes
Must attribute
✓ Yes
Patent grant
✓ Yes
What this license means
The AGPL closes the 'SaaS loophole' in the GPL. If you modify AGPL software and let users interact with it over a network (like a web app), you must make your modified source code available. This is the strongest copyleft license — it ensures that even hosted versions of the software remain open.
When you encounter this license
Be cautious. If you're using an AGPL library as part of your SaaS product, you may need to open-source your entire application. Many companies have blanket policies against AGPL dependencies. Check with your legal team before adopting.
Watch out for
This is the license companies fear most. MongoDB, Grafana, and others have moved to custom licenses (SSPL, BSL) because AGPL was too permissive for their business model while still scaring away enterprise users. If you see AGPL, assume you cannot use it in a proprietary SaaS without legal review.
Tools using GNU Affero General Public License v3.0 (20)
Self-hosted photo/video management
Open observability and data visualization platform
Open source Notion alternative
High-performance S3-compatible object store
Lightweight Bitwarden-compatible server
Open source Jira/Linear alternative
Local LLM interface with text, vision, and training
Open-source foundation for building internal tools
Self-hosted cloud platform
Modern load testing tool
Horizontally-scalable, multi-tenant log aggregation
Find and verify leaked credentials
Lightweight privacy-friendly web analytics
High-performance, self-hosted newsletter manager
Identity infrastructure, simplified
Static site generator for Markdown and reST
Open Multi-Agent Interactive Classroom — Get an immersive, multi-agent learning experience in just one click
Open source form builder
Your personal intelligence agent. Watches the world from multiple data sources and pings you when something changes.
The open LMS by Instructure, Inc.
This guide is for informational purposes only and does not constitute legal advice. For licensing decisions in commercial products, consult a qualified attorney.